Electrical blowtorch



Sept 1925.

J. MOLDOVAN ELECTRI CAL BLOWTORCH Filed May 5' 4 NVENT Patented Sept. 8, 1925.

UNITED STATES PATENT OFFICE.

JOHN MOLDOVAN, OF WHEELING, WEST VIRGINIA.

ELECTRICAL BLOWTORCH.

Application filed May 3,

To all whom it may concern:

Be it known that I, JOHN MoLDovAN, a citizen of the United States, residing at Wheeling, in the county of Ohio and State of West Virginia, have invented certain new and useful Improvements in Electrical Blowtorches, of which the following is a specification.

This invention relates to an electric blow torch and while primarily intended for cleaning casting cores it will be obvious that the device may be employed for any purpose wherein it is found to be applicable.

In foundry practice, the cores of a casting are frequently filled with a compact mixture of sand and metal during the molding operation, which is extremely difficult to remove. It is the common practice to clean such cores by chipping or by the use of an acetylene torch. The former process is very arduous and unsatisfactory, while the use of the acetylene torch is adaptable only for cleaning shallow casting cores as its configuration will ordinarily not permit of its insertion into the core of the casting.

The primary objects of this invention are to provide a device of the type stated, in a manner as hereinafter set forth, which will expedite the cleaning of a casting core, which will remove the materials as the same are loosened by the action of the carbon electrode, and which is conveniently operable to clean a casting core of any depth or configuration.

Further objects of the invention are to provide a torch of the character described which is simple in its construction and arrangement, strong, durable and efficient in its use, positive in its action and comparatively inexpensive to manufacture.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention hereinafter disclosed can be made within the scope of what is claimed without departing from the spirit of the in vention.

In the drawing forming a portion of this specification and wherein like numerals of 1924. Serial No. 710,706.

reference designate corresponding throughout the several views Figure 1 is a side view of an electric blow torch in accordance with my invention.

Figure 2 is a longitudinal sectional view thereof with the clamping jaws and electrode removed therefrom.

Figure 3 is a perspective View of a clamping aw.

Referring in detail to the drawing 1 denotes an elongated body portion, preferably constructed from ordinary metal tube or pipe, which may be provided in lengths to best suit operating conditions.

A metal bushing 2 is detachably mounted on the rear end of the body portion 1 by the threaded connection 3, and a metal sleeve 4 is detachably mounted on the forward end of the body portion 1 by the threaded connection 5.

The bore of the bushing 2 is formed with a transversely extending wall 6, disposed adjacent to the forward end thereof, whereby the bushing bore is divided into a rear bushing bore 7 and a front bushing bore 8.

The bore of the sleeve 4 is likewise formed with a transversely extending wall 9, disposed adjacent to the rear end thereof, whereby the sleeve bore is divided into a rear sleeve bore 10 and a front sleeve bore 11.

It will be noted that when the body portion 1 is connected with the bushing 2 and with the sleeve 4, the passage 12 of the body portion 1 will communicate with the front bushing bore 8 and the rear sleeve bore 10, but not with the rear bushing bore 7 and the front sleeve bore 11.

The front sleeve bore 11 is formed with a rearwardly tapering threaded forward end portion 12, which engages the combined tapering threaded shanks 13 of the pair of clamping jaws 14, for the purpose of dedetachably securing the latter in the sleeve 4 while simultaneously securely clamping the carbon electrode 15 in position in the clamping jaws 14.

Each of the opposed faces of the clamping jaws 14 is formed to provide a concave recess 16, disposed at right angles relatively to the disposition of the associated shank 13 and with a semi-circular recess 17 formed centrally in the marginal forward edge of the clamping jaw 14.

parts Q u v.)

By securing the carbon electrode in the concave jaw recesses 16, the former will be disposed at right angles with the body portion 1 of the device, as shown in Figure 1, of the drawing, and by securing the elec trode 15 in the semi-circular jaw recesses 17, the electrode 15 will be disposed to extend in alignment relatively to the body portitn 1.

The manner of attaching the electrode 15 in the jaws A is determined by conditions found in practice. If the casting core, to be cleaned, is comparatively shallow, the operation of the torch is facilitated by support ing the electrode 15 at right angles with respect to the body portion 1 in the jaw recesses 16, but if the casting core, to be cleaned is of a depth requiring the insertion of the body portion 1 into the casting core itself, the operation of the device is facilitated by supporting the electrode 15 in the jaw recesses 17 to extend in alignment with body portion 1.

A handle member 18 constructed for any suitable insulating material, is permanently fixed on the bushing 2, and a comparatively large circular shield 19 also made of insulating material, is fixed, centrally thereof, to the bushing 2, forwardly of the handle member 18. The shield 19 provides protection for the hands of the operator against heat and sparks attending the operation of the torch.

A compressed air inlet conduit 20 is at tached in the lower marginal edge of the shield 19 having its upper end secured in the forward end of the bushing 2 which projects forwardly from the shield 19, and communicating with the forward bushing bore 8. The conduit 20 is further provided with a regulating valve 21 and a nipple 22 adapted for making a hose connection therewith from the compressed air supply. The valve 21 and nipple .22 are disposed on the conduit 20 in rear of the shield 19.

A compressed air outlet conduit s3 is mounted on top of the sleeve 4 and communicates at its rear end with the rear sleeve bore 10. The outer end of the conduit carries a nozzle 24 which is inclined at an angle to extend between the clamping jaws 14 in close proximity to the carbon electrode 15, for the purpose of concentrating the force of the air blast directly to the work for removing the materials from the casting core 5 as they are loosened by the action of the carbon electrode 15.

The electrical current for energizing the electrode 15 is supplied thereto by utilizing the jaws 14:, sleeve 4, body portion 1 and the bushing 2 as a terminal conductor. One cable conductor 25 from the source of electrical supply is connected in the rear bushing core 7, while the other cable (not shown) of the circuit is grounded on the casting 26 on which the work is being performed.

It will here be noted that the body portion 1 is used both as a conductor for the electrical current and also as a conduit for the passage of the compressed air, and that the carbon electrode 15 will function only while contacting with the composite mixture 27 in the casting core 28, to loosen the mixture 27 without liability of damage to the wall of the casting core.

What I claim is In a device for the purpose set forth, the combination of an elongated tubular body portion, a bushing detachably connected to the rear end thereof, said bushing formed with a bore provided with a transversely disposed wall, a sleeve detachably connected to the front end of said body portion, the bore of said sleeve provided with a transversely disposed wall and with a tapering threaded forward end portion, a pair of clamping jaws having tapering threaded shanks engaging when combined in the said threaded end portion of said sleeve, a carbon electrode clamped in said jaws, a handle member fixed on said bushing, a shield mounted on said bushing forward of said handle member, a compressed air conduit attached to said shield and communicating with said bushing bore forward of the wall of the latter, a compressed air conduit supported by said seleve and communicating with the bore of the latter in rear of the said sleeve bore wall, the outlet of said last mentioned conduit disposed between said pair of jaws in close proximity to said electrode, said body portion constituting a con ductor for supplying electrical current to said electrode and further constituting a compressed air conduit, substantially as described and for the purpose set forth.

In testimony whereof I afiiX my signature.

JOHN MOLD O VAN. 

